Safety Laboratory Features

Unlike water, LNG and LPG have finite volume coefficients of compressibility, and they expand significantly with increasing temperature along the saturation line (see Table 5.1), or with isendialpic and isentropic decreases in pressure. This behaviour is totally unlike that of water, which has almost zero compressibility thus water is a useful liquid, for hydraulic power transmission and pressure testing of vessels. 

If a vessel is overfilled with LNG, then the additional boil-off vapour escaping through the vent-line will create a back-pressure, compressing the liquid. If the additional boil-off is now reUeved by opening a second vent or pressure relief valve, the pressure falls, the liquid may expand from the already full vessel into the ventline, and unexpectedly increases the boil-off mass flow, causing the vent-line pressure to rise still further. What action should be taken  

The first thing to reahse is that the problems of overfilUng a vessel do not stop when the LNG transfer is cut off. The compressibility of the hquid must be anticipated by slowly opening additional vapour vents, without encouraging liquid to expand into the vent-line. 

Secondly, if LNG spills, or sprays, out of the vents, beware of (a) cold bums to personnel, (b) asphyxiation by displacement of breathing air by dense cold vapour and (c) cold damage to carbon steel structures and wet concrete pavings. 

It is therefore important to ensure that emergency procedures are in place that permit the immediate and controlled evacuation of personnel to avoid (a) and (b), and the setting up of water sprays to avoid (c). 

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First, consider efficiency. Many people incorrectly assume that, in the absence of codes, consumers would be helpless against greedy firms. But without codes, builders would compete on the basis of safety and features, and consumers could hire inspectors to evaluate structural quality (which already happens during mortgage inspections). Builders could also hire firms to certify that their structures comply with best practice (the construction equivalent of Underwriters Laboratories). Uncertified builders would be at a quality disadvantage. 

Safety procedures in chemical process facility. Partial contents introduction to corporate safety, laboratory safety and inspections, process area safety features and procedures, DIERs and VSP, dust and vapor explosion apparatus, personal protective equipment, process area inspections, and informal and formal safety reviews. American Institute of Chemical Engineers, 1989. 

We believe that safety is a discipline of chemistry that is comparable with inorganic, organic, analytical, physical chemistry and biochemistry as an important component in your chemical education. As you become educated and build your critical thinking skills in other aspects of chemistry, so too you will need this same kind of in-depth knowledge and understanding to address issues in laboratory safety. This feature of you chemical education will help prevent you and others for injury or even death. 

L.F. Albright C. Hansen, Eds, Industrial and Laboratory Nitrations , ACS Symposium Series 22, ACS, Washington, DC (1976). Excellent modern review. Ten chapters emphasize various aspects of the chemistry and mechanism of nitrations, including oxidation and ipso-nitration side reactions. Six chapters discuss the chemistry and physical transfer steps between phases. Eight chapters discuss plant operation-improvements, safety features, and new operations. The final chapter is devoted to vapor phase nitrations... 

Every laboratory is different. Standard safety features when applied to a given situation may be insufficient in some cases, superfluous in others. There will also be times when work is being done with materials or procedures not covered in available literature. Here the laboratory operator must use a combination of experience, knowledge, and common sense. The last of these may often be the most important. Planning a laboratory and making it operate safely thus becomes a custom procedure. 

Careless Workmanship. One laboratory operator combined a variety of equipment for a distillation procedure and finally came up with something that met his needs. In other words, it worked —but he had a tangle of wires, water hoses, and blocks of scrap wood for support. With less than one day s additional work, he could have improved both performance and safety features. 

Bouin s solution is one of the traditional ways to harden cell pellet. Some cytologists believe it provides the best cellular details, especially nuclear features in cell blocks.28 The major steps are (1) After centrifugation, fix the cell pellet with Bouin s solution. (2) After 2h, discard the solution. (3) Remove the hardened cell pellet from the tube, wrap it with lens paper, and transfer it into a cassette for further processing. We have been using this method for many years. In our experience, most of the time, ICC results are consistent with IHC from the surgical specimen. The biggest drawback of this method is the toxicity of Bouin s fixative which creates biohazard and safety issues for the laboratory. We also found cell blocks gave poor fluorescence in situ hybridization (FISH) results after Bouin s fixation. 

The "P" has been replaced with "BSL" or Biosafety Level. There are four biosafety levels which are defined according to a combination of facility design, laboratory practices and techniques, equipment and health and safety controls. It is not practical to try to completely describe all of the features and definitions pertaining to biocontainment laboratories in a chapter dedicated to an overview of design. Therefore, we will concentrate on the elements of building design for "maximum containment" or BSL-4 facilities. 

Use of medium-scale heat flow calorimeter for separate measurement of reaction heat removed via reaction vessel walls and via reflux condenser system, under fully realistic processing conditions, with data processing of the results is reported [2], More details are given elsewhere [3], A new computer controlled reaction calorimeter is described which has been developed for the laboratory study of all process aspects on 0.5-2 1 scale. It provides precise data on reaction kinetics, thermochemistry, and heat transfer. Its features are exemplified by a study of the (exothermic) nitration of benzaldehyde [4], A more recent review of reaction safety calorimetry gives some comment on possibly deceptive results. [5],... 

The solvent system 70/30 methylene chloride/ hexafluorolsopropanol has been In use In our laboratory since 1977 as a solvent for poly(ethylene terephthalate) (PET) and other semlcrystalllne polar polymers. Some advantages of this solvent are It provides rapid room temperature solubilization It Is transparent at 254 nm (U.V.) It Is a solvent for polystyrene and It Is a minimum boiling azeotrope. Disadvantages are Its low boiling point (36 C) and the potential safety hazard It represents. The combination of appropriate HPGPC equipment and this solvent system reveals heretofore unrecognized features of the molecular weight distributions of polyesters ... 

After the safety features and procedures in your laboratory have been explained to you, make a list of them. 

Become familiar with the location and use of standard safety features in your laboratory. All chemistry laboratories should be equipped with fire extinguishers, eyewashes, safety showers, fume hoods, chemical spill kits, first-aid supplies, and containers for chemical disposal. Any questions regarding the use of these features should be addressed to your instructor or teaching assistant. 

The basic components of a microwave system include a microwave generator (magnetron), a waveguide for transmission, a resonant cavity, and a power supply. For safety and other reasons, domestic microwave ovens are not suitable for laboratory use. There are two types of laboratory microwave units. One uses closed extraction vessels under elevated pressure the other uses open vessels under atmospheric pressure. Table 3.12 lists the features of some commercial MAE systems. 

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